Laundry drying apparatus



Sept. 26, 1961 F. PLUMER 3,001,297

LAUNDRY DRYING APPARATUS Filed July 18, 1957 2 Sheets- Sheet 1 L f6 f7); \A

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3,001,297 {:AUNDRY DRYWG APPARATUS Franz Plumer, Fabriciusstrasse 180, Hamburg, Germany Filed July 18, 1957, 'Ser. No. 672,835 6 Claims. (Cl. 3 4-133) This invention relates to laundry drying devices and more particularly to drying devices in which hot air is circulated through a rotating drum containing laundry to be dried, and is'a continuation-in-part of my application Serial No. 576,453 filed on' April 5, 1956, now abandoned.

It is an object of this invention to provide a new and improved rotating drum' laundry drying machine of increased efiiciency. In prior drying devices of the rotating drum type a stream of air washeated and forced through the drum between inlet and outlet ports. The efiiciency of such drying apparatus depends upon the length of the dry air path through the drum, the longer the path the better the efiiciency. Consequently, it is highly desirable to increase the length of the dry air path through the drum.

, In the present invention the dry air path is lengthened by providing two dry air streams, each of which traverses one half of the length of the drum. This is done by intr'oducing dry air into the two opposite ends of the drum and by sucking the saturated air out of the drum at a point midway between its ends. The eifect of this action is to produce two spiral air currents traveling from the opposite ends of'the drum toward the center thereof where they unite and are sucked out of the drum.

' A further object of the invention resides in the provision of a continuous laundry drying device of the rorating drum type. In accordance with thisobject, the invention provides a rotating drum' open atits opposite ends, and positioned inclined if desired, so that wet laundry may be placed in one end of the drum and removed dry from the other end. By virtue of the fact that the'dry hot air is introduced into the drum at its opposite ends and removed at the center of the drum, substantially none of the hot air, escapes from the open ends of the drum. The arrangement is such that all of the hot air is retained within the drum-and none'passes from-the ends of the drum to annoy the operator and reduce'the efliciency of the machine. As a matter of fact, cool air flows into the drum with a pleasant cooling action on the end faces of the drum. By this inventive arrangement for continuous drying the laundry is not only dried, but is also loosened and separated into single pieces so that the laundry at the discharge end of the drum will fall out or can be easily removed without the necessity of subsequent heating.

The above and other objects and features of the vention will become apparent from the following detailed description taken in connection with the accompanying drawings which form a part of this specification and in which:

'FIG. 1 is a cross sectional view taken online li--1 of FIGURE 4 of one embodiment of the invention,

FIG. 2 is a cross sectional view taken along line 2--2 of FIG. 1;

FIG. 3 is another cross sectional view taken on line 3--3 of FIGURE 4 of the invention similar to that of FIG. 1, but including a cross sectional view of the blower of the dryer.

FIG. 4 is a cross sectional view taken along the line 4-4 of FIG. 3;

FIG. 5 is a cross sectional view of another embodiment of the invention intended for continuous drying operations; and

3,iidl,297

arrows and showing the embodiment of the invention illustrative in FIGURE 5.

Referring to FIGS. l-4 it will be noted that a drum 2' having perforations or openings 20 therein is supported.

for continuous rotation in the direction of arrow 7 on an axle 21. The axle 21 is carried by a backingplate 22 which, in turn, is securely fastened to a stationary housing 1 for the drum. The drum 2 may be provided with interior ribs or grippers laundry along a path which is as the drying air current. Air,

means, not shown, is blown into the drum housing 1 through two inlet slots or ports and by means of a blower 3. From ports 4 the hot air passes through perforations 20 into the interior of the drum where it travels toward the median portion of the drum in two helical streams Z and Z Another opening 6 in plate 24 serves as an exhaust port for the hot air moving in the streams Z and Z midportion of the dryer on the side of the housing opposite from ports 4 so that the three openings are dis It will thus be seen posed in the shape of a triangle. that warm, dry air enters the drum from one side of a vertical plane extending through the axis of the drum while it is discharged through the outlet 5 arranged on the other side of said plane. As will be understood, the arrangement is such that hot dry air entering ports 4 will travel in helical paths Z and Z to the center of the drum from whence it will pass out through port 5 to blower 3. The air is then radially directed toward each of the two end portions of the drum where it again enters the drum through the openings 4.

To prevent the dry air from passing directly to outlet port 5 without passing through the drum 2-, four sealing ribs 6 are provided around the outer periphery of the drum, spaced apart by degrees. In addition, sealing means 9 are provided between the front side of drum 2 and the corresponding wall of housing 1. With this arrangement, four chambers are provided between the drum 2 and housing 1. The lower two chambers are used to accommodate entry and exit of the drying air, while the upper chambers are employed to reduce the current speed of the air and to equalize the same where: by the efiiciency of the apparatus is improved.

In FIGS; 3 and 4 the design of the blower 3 is disclosed. Air enters'the blower in the direction of arrow a and leaves in thedirection of arrow b from whence. it flows into the interior 1a of the drum 2. The pressure channel 8 of the blower 3 is divided into two channels 8a and 911 by the guiding plate 10 which is bent at an in the blower are thrown by centrifugal force outwardly against the wall 8a. From wall 8a they are forced through partial channel 8a and channel 11 to the atmosphere. By adjustment of guiding plate 10 by suit able means, not shown, the cross sectional areas of the. partial channels 8a and 9a can be varied to accommodate diiferent operating conditions.

In FIGS. 5 and 6' the embodiment of the invention shown comprises a longitudinal drum 2L carried within a housing 1 and provided with perforations 20' in its outer wall. An opening 2a at one end of the drum and opening 2b at the other end provide an entrance and exit, respectively, for thelaundry. The drum is carried for rotation on rollers 13 which are supported by hous-' ing 1 for free rotary movement. Sealing members 6 and 9 divide the interior of housing 1 into four chambers similar to those shown and described with reference to FIGS. 1-4. Hot air entering the drum 2L at the Patented Sept. 26, 1961 23 which serve to move thelong as possible through heated by any suitable As shown in FIG. 2, the port 5 is located at the 3, two inlet ports 4 passes in, helical, streams, to, the, outlet channel 5, arranged at the median portion of the drum. From channel 5, the moist air passes through screens 14: and the heaters :12, into; the blower. .3; The. blower, in turn, conveys the hot dry air: through channels:- 9" to the; inlet ports 4 located at the ends offthe drum, 21;. A bafile; plated!) divides; the pressure channel 8 of. the: blower 3;into a moist. air outletchannelll. andlthe. dry air: circulating channel 91" in a. manner; similar to the arrangement shown in. FIGS, 3. and: 4.

The arrangement is such that wet or damp pieces oftlaundry placed in the. drum 2L. through opening 2a; will be tumbled as the drum rotates and forced to theleftuntil they reach opening-2b from which they are dis charged in a dry conditionfrom thev drum. Since the; hot dry air enters the drum from; its opposite ends, very little,.if any, will escapeout of the openings 2a and 2b to reduce .the eificiency'of the apparatus and annoy the operator' who is placing clothes in the opening 211.

7 Although the invention has been described in connection with certain specific embodiments, it willbe reads ily apparent to those skilled in the art that various changes in form and arrangementof parts can be made to suit requirements without. departing from, the spirit andtscope of the invention.

What I claim is:

1'. Ina drying apparatuscomprising astationary'housing-having opposing openings, a horizontalfpartition wall in the lower portion thereof providing a heating chamber anda drying chamber thereabove, an. open ended drum rotatably mounted above the horizontal partition wall in said housing provided with a plurality of perforations distributed throughout, the periphery thereof, spaced l'on gi tudinal sealing strips between the housing and drum forming a series of chambers, openings formed in said partition wall at each end thereof, means: for. heating and circulating air through said drum, duct means; below saidipartition wall for directing air toward each end of. said-'drumand to the openings in saidpartition wall, said airheatingand circulating'rneans being disposed'to: one side 'ofa vertical plane extending through. the: axis of said rotating-drum and communicating withgone of said chambers, said partition wall being provided with an outlet opening located on'the-other side of said vertical plane at a point substantially midway-between the end of said drum communicating with anotherof said chambers and fan means for circulating air throughisaid" air inlets andout of saidair outlet;

2; The combination claimed in claim, liinjwhich said sealing strips are formed by radially e'tnd'inwardl'y ex-v tcnding'ribs on the-inner surface of said housing proje'cting into said drying chamber and slidablyengaging the peripheral surface of said rotary drum, said ribs being arranged in circumferentially spaced longitudinal relation to pcrmitwarm air to pass into the drying chamher-at opposite endsthereof'and travel through a spiral path to the" central portion of the housing and drying chamber where it is returned through the outlet open ing in said partition wall to said other chamber.

3. In a drying apparatus comprising a' stationary housing having' opposing openings, an open ended rotatable drum mounted in said'housing having perforations distributed throughout the periphery thereof, a series of circumferentially spaced axially extending ribs depending from the housing between the inner walls of said housing and the outer periphery of said drum to define a plurality of chambers extending along the axial length oi the drum around the circumference thereof, means for: heating and circulating air located near the opposite ends-of said drum in one of said chambers and offset to one side of a vertical plane extending through the axis of the drum to direct the air in a direction generally parallel to the vertical plane through the drum axis, said last-named means including fan means for circulating dry, hot air into opposite ends of said drum, and duct means in. the, lower. portion oi saidtcasing and ofi'et. on.

the opposite side of said vertical plane extending through the drum axis and arranged in another of said chambers at a point substantially midway between the opposite ends of said drum, said duct meansv being in. communication with the inlet'of'said' fan means for directediair. radially toward each-.ofthe two end portions offthe, drum.

4. In a clothes;drying apparatus comprising a housing having opposing openings, an open ended rotatable drum having cndportions and a plurality of perforations" distributed throughout the periphery thereof, said opposing openings. communicating withthe open ends of saiddrum,

ing ofiset'on the other side of a vertical.planeextending through thedrum axis from: the side onwhich saidtan meansis located and in communication with another of" saidcham-bers atta point substantially Hilda-W213 between the opposite endsof the drum and incommunicationwith theiintake of said fan'means;

5. A combination as set forthin claim 4 whereinthe open ends ofthe drum permit :the feeding oficlothes to' be dried and the discharge-thereof after drying;

6. In a clothes drying'apparatus; comprising a station: aryhousing having opposing openings, an open ended rotatable drum mounted within said housinghaving per? forations' distributed throughout the periphery thereof; the openings in. said housing communicating with; the open ends of thedrurn, a seriesiof axially extending sealing ribs depending from said housing and arrangediin circumferentially spaced apart relation and interposed between the inner walls-of said housing and the.periph-. eral surface of 'said drum to definea plurality of charm hers extending along the axial length of the drum; heat:- ing means arranged one near the'oppositeends of said drumin one of'said chambers-and in the lower portionof said housing oifsetto one side of a verticalplane extending through the drum axis for directing theiair in a direction generally'paraliel to the direction of, the

vertical plane through the drum axis, means for circulating hot air from said heating means including fan means, duct means communicating with said fan means and. directing the air radially toward each of the two end portions ofthe drum so that said air will travel through a spiral circulatory pathway in the drum toward the intermediate portion thereof, and an exhaust channel in the lower portion ,ofsaid'housing for said air having communicationwith one of said chambers at a point substantially mid-Way between the opposite ends of said drum and arranged on the other side of the vertical plane e3- tending through the. (1mm axis and offset therefrom, and means including a duct forconducting the air passing through said exhaust channel to the intake of said fan means.

Q References (Cited in the file of this patent UNITED STATES PATENTS said chambers being.

axial length of said drum, means 

